Which descriptions of the Ottoman Empire are accurate? Choose all answers that are correct.
a. at its height, included territory that is now part of Turkey, Greece, and Egypt
b. had a brief moment of glory before being conquered by Mongols
c. founded by Osman in the thirteenth century
d. as Sunni Muslims, experienced frequent conflict with Safavid Shi'ites
e. expanded through Africa and Asia but could not successfully invade Europe